femaleWhen cancer cells take over a cell lineIt is reorganized in the direction of pursuing growth.One Cancer cells stop cellular processes that do not serve this goal. research Research published in the journal Nature Nanotechnology, Researchers found that reactivating the dormant pathway inhibited the spread of cancer.2 These findings herald the birth of new treatments that target cancer cells more effectively.
Jinda YongJin, a materials scientist at the University of Technology Sydney and co-author of the study, approaches big questions in science using the smallest tools: nanoparticles. Jin has previously used nanoparticles to look inside. marrow And detect fine molecules Released by cancer cells.3,4 His latest research was even more ambitious: He wanted to see if tiny nanostructures could treat cancer.
His team took inspiration from what came before. research Researchers have been working on liver and kidney cancers to manipulate the cancer cells’ metabolism to restore healthy cellular processes and limit their growth. 5 Jin wondered whether a nanoparticle-based delivery system could more easily alter the inner workings of cancer cells. For the experiment, Jin’s team focused on skin cancer. Melanoma cells slow down the production of the pigment molecule melanin in order to convert energy into cell proliferation. The first challenge Jin’s team faced was finding a way to accelerate melanin production.
Interventions that alter the way the internal processes of a cell work often target metabolic enzymes. Developing enzyme activators is a challenging process, and the resulting drugs are typically Cleared It is eliminated from the body before it takes effect.6 Another option is to identify and provide the nutrients that cells use during melanin production. In skin cells, the amino acid tyrosine is an essential component of melanin synthesis, but Deliver Delivers amino acids to specific cells.7 This is where nanotechnology excels.
“We engineered the natural form of tyrosine to create the minicell structure,” Jin said. These minicells, also called nanomicelles, are tiny spheres about 60 nanometers in diameter that can easily pass through the cell membranes of cultured mouse or human cancer cells. After three days of culture, Jin and his team found that the target cells had a sixfold increase in melanin levels compared to control cells that had not been exposed to the minicells.
Now, the cancer cells that were secreting melanin soon ran out of energy. Further analysis showed that as the concentration of minicells increased, the cancer cells were less likely to spread.
The researchers used a mouse model of melanoma to test the minicells in a living system. When they first injected the minicells intravenously, they thought something was wrong. The tumors darkened, which led the team to think the cancer had become more aggressive. After all, as Jin points out, melanoma means “black tumor.”
Instead, the researchers found that the darker color of the tumors indicated higher melanin production and cancer cell death. After 50 days of treatment, the minicells had crawled out of the tumor growth hole and significantly extended survival.
These are all signs of successful treatment, but he points out that modern medicine rarely treats cancer on its own. Navdeep ChandelA cell biologist at Northwestern University who was not involved in this study.
Jin and colleagues decided to test a combination of the minicells and an experimental treatment called photothermal therapy, which uses the newly increased levels of melanin in the tumors. They shined an 808-nanometer infrared laser on the tumors of mice for six days, five minutes each day. The melanin absorbed the light, heating the tumor cells. As Jin said, it left the surrounding normal tissue unharmed, eradicating the tumors and increasing survival rates compared to the treatment with the minicells alone.
Chandel said the results are promising but require more study. “First, we want to see it in multiple mouse models, and second, we want to see it in standard-of-care settings,” he said.
Standard treatments such as radiotherapy or chemotherapy may interact negatively with new approaches. For example, chemotherapy induces oxidative stress to kill tumor cells, but in clinical trials Shown Antioxidant treatment reduces the effectiveness of chemotherapy.8
In the future, Jin hopes that minicells could be incorporated into early-stage interventions before chemotherapy or radiation is needed. “If we can prevent cancer… we won’t have to worry about limited treatment options,” he concludes.
